EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne magnetic measurements. It is a significant update of our previous candidate grid for the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid. Additional grid and track line data have been included, both over land and the oceans. Wherever available, the original shipborne and airborne data were used instead of precompiled oceanic magnetic grids. Interpolation between sparse track lines in the oceans was improved by directional gridding and extrapolation, based on oceanic crustal age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP satellite magnetic field model MF6.

Format specification:
A georeferenced TIFF (GeoTIFF) with a resolution of 2 arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.

Format specification:
A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application. The color scale legend is at http://geomag.org/models/EMAG2/EMAG2_scale.png

Produced by the NOAA National Geophysical Data Center. Not subject to copyright protection within the United States.

Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series.

While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.